Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124202, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38565052

RESUMO

A groundbreaking optical sensing membrane has been engineered for the accurate assessment of copper ions. The pliable poly(vinyl chloride) membrane is formulated through the integration of sodium tetraphenylborate (Na-TPB), 4-(2-hydroxy-4-nitro azobenzene)-2-methyl-quinoline (HNAMQ), and tri-n-octyl phosphine oxide (TOPO), in conjunction with o-nitrophenyl octyl ether (o-NPOE). The sensor membrane undergoes a thorough investigation of its composition to optimize performance, revealing that HNAMQ serves a dual role as both an ionophore and a chromoionophore. Simultaneously, TOPO contributes to enhancing the complexation of HNAMQ with copper ions. Demonstrating a linear range for Cu2+ ions spanning from 5.0 × 10-9 to 7.5 × 10-6 M, the proposed sensor membrane showcases detection and quantification limits of 1.5 × 10-9 and 5.0 × 10-9 M, respectively. Rigorous assessments of potential interferences from other cations and anions revealed no observable disruptions in the detection of Cu2+. With no discernible HNAMQ leaching, the membrane demonstrates rapid response times and excellent durability. The sensor exhibits remarkable selectivity for Cu2+ ions and can be regenerated through exposure to 0.05 M EDTA. Successful application of the sensor in determining the presence of Cu2+ in biological (blood, liver and meat), soil, food (coffee, black tea, sour cherry juice, black currant, and milk powder) and environmental water samples underscores its efficacy.


Assuntos
Colorimetria , Cobre , Cobre/análise , Cátions , Chá , Alimentos
2.
Heliyon ; 9(9): e20193, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809404

RESUMO

Nowadays, several engineering applications and academic investigations have demonstrated the significance of heat transfers in general and mixed convection heat transfer (MCHT) in particular in cavities containing obstacles. This study's main goal is to analyze the MCHT of a nanofluid in a triangular cavity with a pentagonal barrier using magneto hydrodynamics (MHD). The cavity's-oriented walls are continuous cold temperature, whereas the bottom wall of the triangle and all pentagonal obstacle walls are kept at a constant high temperature. For solving governing equations, we utilized the Galerkin's finite element approach. Four dimensionless factors, Richardson number (0.01 ≤ Ri ≤ 5), Reynolds number (10 ≤ Re ≤ 50), Buoyancy ratio (0.01 ≤ Br ≤ 10) and Hartmann number (0 ≤ Ha ≤20) are examined for their effects on streamlines, isotherms, concentration, velocity, and the Nusselt number. Also, with the help of Taguchi method and Response Surface Method (RSM) the optimization of the studied dimensionless parameters has been done. The optimum values of Ri, Re, Ha and Br are obtained 4.95, 30.49,18.35 and 0.05 respectively. Ultimately, a correlation has been extracted for obtaining the optimum average Nusselt number (Nu) in mentioned cavity.

3.
J Neonatal Perinatal Med ; 12(2): 173-178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30829621

RESUMO

INTRODUCTION: High frequency jet (HFJV) and oscillatory (HFOV) ventilation were used to rescue newborns with congenital diaphragmatic hernia (CDH), who failed conventional mechanical ventilation (CV). Changes in ventilator settings and pulmonary gas exchange were evaluated following transition to high frequency ventilation (HFV). METHODS: Records of patients with CDH rescued with HFV prior to surgical intervention between 2006 and 2015 were reviewed. Mean airway pressure (Paw) and arterial blood gases during CV and those obtained within the first hour of HFV were compared. A composite repeated measure analysis was performed to evaluate longitudinal and intergroup variances. RESULTS: Twenty-seven patients were rescued from CV, 16 by HFJV and 11 by HFOV. The two groups had similar gestational ages and birth weights. Prior to HFV, both groups had similar Paw, PaCO2, FiO2 and PaO2. HFV was associated with a significant improvement in ventilation, and the rate of decrease of PaCO2 was no different between groups. There was a significantly higher increase in Paw increase with HFOV compared to HFJV. CONCLUSIONS: In newborns with CDH rescued with HFV, ventilation improved but Paw was significantly lower in patients supported with HFJV compared to HFOV.


Assuntos
Hérnias Diafragmáticas Congênitas/cirurgia , Ventilação de Alta Frequência/métodos , Insuficiência Respiratória/terapia , Gasometria , Oxigenação por Membrana Extracorpórea , Feminino , Hérnias Diafragmáticas Congênitas/complicações , Herniorrafia , Ventilação em Jatos de Alta Frequência/métodos , Humanos , Recém-Nascido , Masculino , Pressão Parcial , Pressão , Troca Gasosa Pulmonar , Respiração Artificial/métodos , Insuficiência Respiratória/etiologia , Estudos Retrospectivos
4.
J Neonatal Perinatal Med ; 7(2): 107-11, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25104120

RESUMO

AIM: We evaluated the use of prenatal steroids (PNS) and the effect of that practice on hospital mortality of late preterm infants with complex congenital heart defects (CHD). METHODS: Retrospective review of records of late preterm infants with complex CHD infants that were cared for in a single tertiary perinatal center between 2002 and 2009. Multivariate logistic regression analysis was performed to determine which of the risk factors commonly associated with death prior to discharge from the hospital predict the outcome (hospital death). RESULTS: Of the 106 late preterm infants with complex CHD, 31(29%) died and 15 (14%) received PNS. Endotracheal intubation in the delivery room (42% vs 15%), necrotizing enterocolitis (10% vs 0%) and hypoplastic left heart syndrome (52% vs 25%) were statistically more frequent in non-surviving infants. Non-surviving infants were more frequently treated with PNS (23% vs 11%) but this difference was not statistically significant (p = 0.131). Using logistic regression analysis, delivery room intubation (OR 4.91; 95% CI 1.78 - 13.51) and the hypoplastic left heart syndrome (OR 3.29; 95% CI 1.28 - 8.48), but not prenatal steroids were independently associated with increased risk of hospital death. CONCLUSIONS: In a selected population of late preterm infants with complex CHD, prenatal steroid treatment did not independently influence survival.


Assuntos
Desenvolvimento Fetal/efeitos dos fármacos , Cardiopatias Congênitas/tratamento farmacológico , Troca Materno-Fetal/efeitos dos fármacos , Cuidado Pré-Natal , Esteroides/administração & dosagem , Feminino , Idade Gestacional , Cardiopatias Congênitas/mortalidade , Cardiopatias Congênitas/fisiopatologia , Mortalidade Hospitalar , Humanos , Síndrome do Coração Esquerdo Hipoplásico , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro , Masculino , Gravidez , Prognóstico , Estudos Retrospectivos , Fatores de Risco
5.
J Perinatol ; 32(1): 51-4, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21546940

RESUMO

OBJECTIVE: We evaluated the effect of late preterm delivery (34 to 36 weeks) on hospital mortality of infants with congenital heart defects (CHDs). STUDY DESIGN: Retrospective record review of infants with major CHD born at or after to 34 weeks, cared for in a single tertiary perinatal center between 2002 and 2009. Factors associated with death before discharge from the hospital were ascertained using univariate and multivariate analyses. RESULT: Of the 753 infants with CHD, 117 were born at late preterm. Using logistic regression analysis, white race (OR; 95% CI) (0.60; 0.39 to 0.95), late preterm delivery (2.70; 1.69 to 4.33), and need for intubation in the delivery room (3.15; 1.92 to 5.17) were independently associated with hospital death. CONCLUSION: Late preterm birth of infants with major CHDs was independently associated with increased risk of hospital death compared with delivery at more mature gestational ages.


Assuntos
Cardiopatias Congênitas/mortalidade , Doenças do Prematuro/mortalidade , Análise de Variância , Feminino , Idade Gestacional , Mortalidade Hospitalar , Humanos , Lactente , Recém-Nascido , Análise Multivariada , Gravidez , Nascimento Prematuro/mortalidade , Estudos Retrospectivos , Fatores de Risco
6.
Environ Monit Assess ; 183(1-4): 65-75, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21340547

RESUMO

This study was carried out in metropolitan Kuwait with a sound level meter to assess peak hour and off-peak hour noise level. In local/collector streets, noise ranged between 56.0 to 79.2 dBA and 55.3 to 76.4 dBA; in arterial streets, 62.3 to 89.2 dBA and 59.6 to 78.9 dBA; and in freeways, 66.7 to 94.8 dBA and 64.9 to 89.1 dBA during peak and off-peak hour respectively. Values were higher than their prescribed standards which may pose a significant impact on quality of life. Findings of this research have shown that the level of traffic-generated noise pollution in Kuwait urban area is high enough to adversely affect the human health and well-being of its residents. Over 1,400 subjects responded to a randomly administered survey that assessed the physical health, personal well-being, and mental health. People residing in neighborhoods exposed to higher noise levels have significantly higher stress and noise annoyance levels and also adversely affected their sense of well-being. In the responder analysis, those people living in quiet neighborhoods had significantly higher mean scores in general health (35 points higher, p < 0.05), sense of vitality (30 points higher, p < 0.05), and mental health (20 points higher, p < 0.05) when compared to the other group. In addition, the component scores of stress and noise sensitivity for the participants living in quiet neighborhoods had significantly lower values (30 points lower and 59 points lower, respectively) than that of the participants living in noisy neighborhood. With the rapid expansion of the infrastructures in metropolitan Kuwait, it is virtually definite that traffic noise will shortly assume a dangerous dimension, and will be a ground of escalating fear for both the public and liable policy-makers. The quality of life in metropolitan Kuwait will certainly be negatively affected.


Assuntos
Exposição Ambiental/efeitos adversos , Ruído dos Transportes/efeitos adversos , Adulto , Feminino , Humanos , Kuweit , Masculino , Saúde da População Urbana
7.
J Pharm Biomed Anal ; 43(4): 1465-9, 2007 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-17045771

RESUMO

The electrochemical behavior of glipizide at the hanging mercury drop electrode (HMDE) was studied in B-R universal buffers of pH 1.7-11. The voltammograms exhibited a well-defined 4-electron irreversible cathodic peak which attributed to reduction of the two C=N of the pyrazine ring of glipizide molecule. Glipizide was found to has an interfacial adsorptive character onto the mercury electrode surface. A monolayer surface coverage of 1.02x10(-10)mol cm(-2) was estimated and hence each adsorbed glipizide molecule occupied an area of 1.63 nm(2) onto the mercury electrode surface. A simple and precise square-wave adsorptive cathodic stripping (SWAdCS) voltammetric procedure was described for quantification of bulk glipizide with a limit of detection of 1.5x10(-10)M and a limit of quantitation of 5x10(-10)M. The proposed procedure was successfully applied for quantitation of glipizide in its pharmaceutical formulation (Minidiab tablets) without interference from excipients.


Assuntos
Glipizida/sangue , Glipizida/química , Hipoglicemiantes/sangue , Hipoglicemiantes/química , Soluções Tampão , Eletroquímica/métodos , Eletrodos , Humanos , Concentração de Íons de Hidrogênio , Estrutura Molecular , Preparações Farmacêuticas/análise , Preparações Farmacêuticas/sangue , Preparações Farmacêuticas/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos
8.
J Pharm Biomed Anal ; 42(4): 523-7, 2006 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-16782297

RESUMO

A fully validated simple, sensitive and selective square-wave stripping voltammetry procedure was described for the trace quantification of cefoperazone in bulk form, formulations and human serum/plasma. The procedure was based on reduction of the adsorbed drug onto a hanging mercury drop electrode. The procedural conditions were optimized as: frequency=60Hz, scan increment=8mV, pulse amplitude=25mV, preconcentration potential=-0.3V (versus Ag/Ag/KCl(s)), preconcentration duration=60-150s and an acetate buffer of pH 4.2 as a supporting electrolyte. A limit of detection of 4.5x10(-10)M and a limit of quantitation of 1.5x10(-9)M bulk cefoperazone were achieved following preconcentration of the drug onto the hanging mercury drop electrode for 150s. The proposed square-wave adsorptive cathodic stripping voltammetric procedure was successfully applied for trace quantification of cefoperazone in human serum and plasma. The achieved limits of detection and quantitation of the drug in human serum were 6x10(-10)M (0.375ngml(-1)) and 2x10(-9)M (1.250ngml(-1)), respectively. The pharmacokinetic parameters of cefoperazone in plasma of hospitalized volunteers were successfully estimated.


Assuntos
Antibacterianos/farmacocinética , Cefoperazona/farmacocinética , Eletroquímica/métodos , Antibacterianos/análise , Antibacterianos/sangue , Antibacterianos/química , Cefoperazona/análise , Cefoperazona/sangue , Cefoperazona/química , Eletrodos , Humanos , Masculino , Mercúrio , Valores de Referência , Reprodutibilidade dos Testes
9.
J Perinatol ; 26(4): 210-4, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16554850

RESUMO

INTRODUCTION: Birth of very low birth weight (VLBW) infants outside subspecialty perinatal centers increases risk for death and major morbidities. OBJECTIVE: The purpose of this study is to evaluate barriers to utilizing a regional perinatal center for the birth of VLBW infants to mothers not living in the immediate vicinity of the center. METHODS: We conducted a retrospective cohort study of VLBW infants residing in the catchment area of a community level II, Specialty Neonatal Unit (SN) admitted to a Regional Subspecialty Neonatal Intensive Care Unit (RC) between January 1999 and December 31, 2004. Maternal demographics and prenatal care as well as outcomes were compared by place of birth. RESULTS: Out of 98 VLBW infants admitted to the RC, 49 (50%) were delivered outside the RC (out-born) and 49 (50%) were born at the RC (in-born). There was no statistical difference in insurance coverage, race, gestational age, severity of illness or maternal demographic factors between out-born and in-born infants. Less than adequate prenatal care rather than distance of maternal residence from the RC was associated with birth outside the RC. Adjusting for prenatal care, distance of residence from the RC increased the risk for delivering outside the center in the subset of mothers insured by Medicaid. CONCLUSIONS: Mothers of VLBW infants who received less than adequate prenatal care and did not live in the vicinity of a subspecialty center had an increased risk for delivery outside that center compared to those with adequate care. Appropriate place of birth for VLBW infants to low-income mothers may be influenced by the distance of their residence to an RC.


Assuntos
Hospitais de Distrito/estatística & dados numéricos , Maternidades/estatística & dados numéricos , Recém-Nascido de muito Baixo Peso , Assistência Perinatal/estatística & dados numéricos , Pobreza/estatística & dados numéricos , Estudos de Coortes , Feminino , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Recém-Nascido , Medicaid/estatística & dados numéricos , Michigan , Gravidez , Cuidado Pré-Natal/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Revisão da Utilização de Recursos de Saúde
10.
Breast ; 15(5): 635-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16488148

RESUMO

A study was carried out to examine the impact of development in image guided needle biopsy on the outcome of mammographically detected indeterminate microcalcification. Between 01.04.1991 and 31.03.2001, the South East London Breast Screening Programme detected 392 cases of indeterminate microcalcificaton. Histological diagnosis was obtained using open biopsy, fine needle aspiration cytology (FNAC), 18/14 G wide bore needle core biopsy (WBNCB) and 11 G vacuum assisted core biopsy (VACB). The study period group was divided into two. Group A (between 01.04.1991 and 31.03.1996) and group B (between 01.04.1996 and 31.03.2001). There was a significant reduction in the benign open biopsy rate in group B compared to group A (25% vs. 51%) (P=0.0001). Of the malignant cases, there is a higher percentage of ductal carcinoma in situ (DCIS) in group B compared to group A (77% vs. 62%). In conclusion, the implementation of more effective methods of image guided biopsy has led to a 50% reduction in benign open biopsies for indeterminate microcalcification and to an increase in the detection of DCIS.


Assuntos
Biópsia por Agulha/métodos , Doenças Mamárias/diagnóstico por imagem , Doenças Mamárias/cirurgia , Mamografia/métodos , Radiografia Intervencionista/métodos , Doenças Mamárias/epidemiologia , Doenças Mamárias/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Calcinose/diagnóstico por imagem , Calcinose/epidemiologia , Calcinose/patologia , Calcinose/cirurgia , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/epidemiologia , Carcinoma Intraductal não Infiltrante/patologia , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma Lobular/diagnóstico por imagem , Carcinoma Lobular/epidemiologia , Carcinoma Lobular/patologia , Carcinoma Lobular/cirurgia , Feminino , Humanos , Londres/epidemiologia , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Técnicas Estereotáxicas , Vácuo
11.
Exp Lung Res ; 25(3): 245-59, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10352954

RESUMO

Intercellular adhesion molecule-1 (ICAM-1) is an adhesion protein involved in immune and inflammatory cell recruitment and activation. In normal, uninflamed adult rat lung, ICAM-1 is expressed at high levels on type I alveolar epithelial cells and is minimally expressed on type II cells. ICAM-1 expression by alveolar epithelial cells in vitro is a function of the state of cellular differentiation, and is regulated by factors influencing cell shape. Based upon this observation, we hypothesized that ICAM-1 expression by fetal lung epithelial cells is developmentally regulated. To investigate this hypothesis, rat and human lung tissues were obtained at time points that represent the canalicular, saccular, and alveolar stages of development. The relative expression of ICAM-1 protein and mRNA were determined in rat lungs from gestational days 18 and 21 (term = 22 days), from day 8 neonatal rats, and from adult rats. ICAM-1 protein was detectable at low level on day 18 and increased progressively during development. Relative expression of ICAM-1 protein was maximal in adult lung. Expression of ICAM-1 mRNA paralleled that of ICAM-1 protein. By immunohistochemical methods in rat and human lung, ICAM-1 was expressed at low level on cuboidal and flattening epithelial cells in the developing alveolar space at the canalicular and saccular stages; however, ICAM-1 expression was increased as epithelial cells spread and flattened during alveolarization. ICAM-1 was predominantly expressed on type I cells rather than type II cells at the alveolar stage in both the rat and human lungs. Thus, relative ICAM-1 expression progressively increased during lung development. ICAM-1 expression is correlated with the increase in surface area as alveolar structures develop and type I cell differentiation takes place. These data indicate that alveolar epithelial cell ICAM-1 expression is developmentally regulated.


Assuntos
Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Molécula 1 de Adesão Intercelular/genética , Alvéolos Pulmonares/metabolismo , Adulto , Animais , Animais Recém-Nascidos , Western Blotting , Desenvolvimento Embrionário e Fetal , Células Epiteliais/citologia , Feminino , Idade Gestacional , Humanos , Técnicas Imunoenzimáticas , Molécula 1 de Adesão Intercelular/biossíntese , Gravidez , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/embriologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley
14.
J Parasitol ; 73(3): 494-502, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3598799

RESUMO

Light and electron microscopic observations confirmed that Eimeria necatrix sporozoites first enter villous epithelial cells of the chicken small intestine and are transported to the crypts by mononuclear cells. Ultrastructurally, these cells resemble granulated intraepithelial lymphocytes (IEL) rather than macrophages, as suggested previously. The injection of chickens intraperitoneally (i.p.) with a variety of irritants, including proteose peptone, at the time of oocyst inoculation or up to 12 hr postinoculation (PI) resulted in a delay in the arrival of sporozoites at the crypt. Significantly fewer sporozoites had arrived at the crypt by 24 hr PI in i.p.-injected birds as compared to controls. This delay in the arrival of sporozoites at the crypts was reflected by a delay in the development of intestinal lesions and in peak oocyst production. However, there was no significant decrease in the total numbers of oocysts produced by these birds as compared to controls, indicating that no significant loss of sporozoites occurs during the possible rerouting of the parasites. The presence of infective stages in extraintestinal sites was detected by transferring various tissues to coccidia-free recipients. Infection was transferable by gut, liver, and spleen from irritant-injected and control birds at all time intervals studied (12, 24, 36, and 48 hr PI). Infection was also transferable with blood and kidney, but not consistently. A small number of oocysts was passed by the recipients of peritoneal wash from irritant-injected birds at 12 hr PI. In all transfers, the prepatent period was normal, suggesting that the migrant stages are sporozoites.


Assuntos
Galinhas/parasitologia , Eimeria/fisiologia , Irritantes/farmacologia , Animais , Injeções Intraperitoneais , Intestino Delgado/parasitologia , Intestino Delgado/ultraestrutura , Irritantes/administração & dosagem , Linfócitos/parasitologia , Movimento , Contagem de Ovos de Parasitas
17.
Parasitology ; 86 (Pt 3): 391-8, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6877865

RESUMO

The development of second generation schizonts of Eimeria necatrix and E. tenella was studied with the electron microscope. Invasion of the crypt epithelial cells by merozoites of the first generation schizonts caused changes in the morphology of the infected cells and stimulated their migration into the lamina propria through breaks which appeared in the basement membrane of the crypts. Second generation schizonts developed in the lamina propria within these crypt cells whose epithelial origin was confirmed by their interconnection by desmosomes and tight junctions and by their possession of characteristic microvilli. A comparison is made between this invasion of the lamina propria by parasitized cells and invasion of connective tissue by malignant epithelial cells; the possible mechanisms involved are discussed.


Assuntos
Ceco/parasitologia , Galinhas/parasitologia , Eimeria/crescimento & desenvolvimento , Intestino Delgado/parasitologia , Animais , Membrana Basal/parasitologia , Eimeria/patogenicidade , Epitélio/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...